Both. With digital radios, they can cut out eavesdroppers, as well as cut out background noise, signal distortion, interference from electronics, as well as interference from people not authorized to transmit on the frequency. It's basically a large private conference call.

BostonUrbEx wrote:Is the switch to digital so people cannot listsen in (for "security" reasons)? Or is it superior in signal strength/some other means?

Digital by itself doesn't mean it can't be heard, there are digital radio scanners(at a much higher price than analog). The radio system the T accepted however, is not listenable by any digital scanner. Digital radio has been promoted as being superior to analog, but that is assuming it's properly implemented, there are systems out there(non-transit) that have been a nightmare for the users.

According to Radio Reference, the ProVoice standard can indeed be monitored by a software package. I won't link the exact page, but if you Google "m/a com provoice" you can find the information. It would be a bit complex to setup, but it seems to be possible. Check your local laws first though. I do not know if it is technically encrypted which would make its reception illegal or not and will not speculate.

MattW wrote:According to Radio Reference, the ProVoice standard can indeed be monitored by a software package. I won't link the exact page, but if you Google "m/a com provoice" you can find the information. It would be a bit complex to setup, but it seems to be possible. Check your local laws first though. I do not know if it is technically encrypted which would make its reception illegal or not and will not speculate.

MNCRR9000 wrote:What type of portables is the mbcr using ? I gather that they are probably not using the digital radios.

They can continue to use the motorolas until the switchover is ready for them, then they have no choice but to go to m/-com systems.

Luckily, Harris bought the tyco business unit which bought m/a-com and since Harris is a major federal contractor (read this as the sole provider of radios to the federal government in recent memory), they are showing an initiative to make opensky and p25 interoperable (http://pspc.harris.com/Solution/NetworkFirst.aspx).

Frankly buying tyco'a bu and doing network first is in their own interest, interoperable systems benefit Harris more than harm it.

The commuter side will remain analog, as will other railroads. Some railroads have bought digital capable radios, but for now they will remain analog. The only things on the T going digital and non-listenable are the non-railroad rapid/streetcar/bus lines.

Just for information sake, the MBTA went digital to allow a dispatcher and driver/operator to converse without interfering with other calls, broadcasts and emergencies. It wasn't to shut the public out. Since a large number of sub channels are possible, it would be difficult to monitor. Of course - in this day and age - anything can be hacked.

Gerry. STM/BSRA

The next stop is Washington. Change for Forest Hills Trains on the Winter St. Platform, and Everett Trains on the Summer St. Platform. This is an Ashmont train, change for Braintree at Columbia.

Also this was also done so all lines, PD, etc could talk to each other in any situation without having to go through OCC and the OCC can patch or link the radios with their consoles too. Only exception when there would be no two way radio's used is for a suspicious package or suspicious item. The reason is because the two way transmission my inadvertently set off the trigger if it is an explosive device.